When climbing a static line, for example a rope secured to a high tree branch, it is common to use one or more ascenders to ease the effort required for climbing. “Ascenders” are generally devices that are threaded or otherwise engaged with a line and enable a climber to move the ascender along the length of the rope in one direction. Attempts to move the ascender in the opposing direction cause the ascender to lock in place, wherein a gripping mechanism operates to prevent movement in that direction, often by the engagement of teeth, ribs or other such protrusions on a cam or other movable surface that may optionally be spring biased. In this manner, ascenders can be advanced along the rope by pushing or pulling, and then bear the partial or full weight of the climber without moving in the opposite direction of travel along the rope. Auto-locking or auto-braking belay devices are also similar devices that allow movement in one direction, and while primarily used to travel down a rope, may sometimes be used in a similar manner to ascend.
It is common for climbers to utilize two ascenders in a climbing system in order to more easily and readily ascend one or more static lines. In those cases, the ascenders typically are advanced in an alternating fashion, with one ascender bearing the weight of the climber while the other ascender is being advanced. In this manner, a climber may reciprocally advance the ascenders to ascend a rope.
In many situations, rope climbers desire increased climbing speed and safety. For example, for professional climbers such as arborists and emergency rescue personnel, rope climbing is a task that may be performed many times on a daily or otherwise frequent basis. Under those circumstances, it may be desirable to decrease the effort required in rope climbing, and to increase the speed and safety of an ascent, potentially saving lives, time and effort over the long-term. Ascenders generally offer such gains, but current climbing systems suffer from several disadvantages that have not been addressed to date.
For example, many known systems include the use a foot ascender. A “foot ascender” commonly refers to an ascender device attached or integrated into the footwear of the climber. Thus, the use of foot ascenders results in one climber's foot—typically the dominate foot—being adjacent to the position of the ascender as the rope is climbed. The leg to which the foot ascender is attached is contracted to move the ascender along the rope, and then the leg is extended causing the foot ascender to lock in place, receiving the weight of the climber ascending the line. Two foot ascenders may be used, but is considered impractical, however, in that any two ascenders on a single static line are not able to be advanced past each other without disengaging one of them from the line, resulting in a relatively unnatural gait. Therefore, several climbing systems have been developed to overcome this disadvantage in an effort to separate the ascenders on the line a distance that will allow for a greater range of movement.
One such example of a known climbing system is described by Spraggon in United States Publication No. 2013/0133981 A1. Spraggon describes the use of an ascender separated from a handle by a connection of a length such that, in use, the ascender is attached to a single rope suspended from above with a second, handled ascender below it. Both ascenders may include foot attachments depending therefrom into which the climber inserts a foot. The ascenders may each then be advanced along the rope in a reciprocating fashion wherein the climber pushes each ascender upwardly while shifting the climber's weight to the foot attachment corresponding to the opposite ascender. The climbing system described by Spraggon and other similar setups incorporating two hand ascenders, however, require that at least one, or both ascenders be attached to the rope at or above the climber's head or chest assembly, which poses significant safety problems to the climber. Furthermore, these systems require the climber to engage his or her hands with the handled ascenders during an ascent, fully occupying the hands.
Other known systems may combine a foot ascender with a handled ascender associated with a foot attachment depending therefrom, but do not overcome the safety issues presented by use on a rope above safety harness assembly tie-in point. The use of one hand and one foot ascender also generally does not provide for a completely hands-free experience, which is considered safer and more desirable. Furthermore, these and other types of unbalanced systems are a serious health concern in that their repetitive use leads to maladies such as hip dysplasia.
Current known systems that attempt to address these issues commonly utilize a foot ascender in combination with a knee ascender. A “knee ascender” refers generally to a device that includes an ascender with a foot attachment (e.g., a loop of rope) depending therefrom at such a length that, when a climber has both legs extended, the ascender portion of the knee ascender device is located at a position on the rope that is approximately level with the knee area of the opposing leg (wherein the foot ascender on that opposing leg remains at boot level). The distance from the foot to the knee approximates a comfortable distance such that the ascenders may be reciprocally advanced, thereby enabling a climber to “walk” up a rope. Knee ascenders typically must include a means for advancing or “tending” the device on the rope in the direction of travel, because there are no handled ascenders by which the climber may use his or her hand to manually advance the ascender.
There are several variations on the use of knee and foot ascender combination climbing systems known in the art. Some systems connect the ascender portion of the knee ascender device to the safety harness attachment point that is typically level with the chest area of the climber by way of an elastic connection. The elastic connection is entirely external to the rest of the knee ascender assembly. When the leg associated with the knee ascender is fully extended and weight-loaded, the elastic connection is under tension. The climber shifts advances the foot ascender along the line by raising the leg associated with the foot ascender, and then shifts his or her weight to that leg. The leg associated with the knee ascender is then raised, and the elastic connection contracts, thereby self-tending the knee ascender along up the rope. These systems, however, do not provide a climber with a full range of motion with regard to his or her legs, because the relatively short distance between the knee area and the chest area results in a tending force that is insufficient to fully advance the knee ascender.
Other systems have been developed to overcome this disadvantage, but none have been able to provide a climber with the use of the legs' full range of motion in a safe and desirable manner. Some climbers extend the length of the elastic connection by extending the connection up and around their neck and shoulders and connecting the end to the harness. This method presents seriously dangerous problems that can be fatal during a fall, and furthermore present an uncomfortable setup that may at the very least chafe and rub against the climbers' shoulders and neck area. Some known systems make use of a bulky pulley system that is integrated into the safety harness to loop the elastic connection around the chest assembly and back down to a lower connection point. These types of systems are bulky, add significant weight to climbing gear, and present multiple lengths of rope, line or cords that get in the way while climbing. Furthermore, they can be much more difficult to don prior to climbing or remove once the destination has been reached, causing significant time delays and safety concerns for regular professional climbers.
It is very desirable from a safety perspective for the loads experienced by climbing ropes to, under routine operation, not meet or exceed safety limits recommended by the manufacture. In the context of elastic cords for which repetitive elongation is expected, the desired length of elongation should be achieved under operating loads that are in a range that will not lead to unwanted or unsafe consequences, such as inelastic elongation, yield and the like. For elastic cords under such linear-elastic range loads, a greater overall length will permit a proportionally greater extension length, according to Hooke's Law. However currently known methods of increasing the expected elongation length of the elastic connection in knee ascenders (and hence the total travel available for the legs) are either grossly unsafe, or the solution results in many exposed lengths of elastic connection that can be cumbersome and unsafe.
It is therefore an unmet need in the prior art for a rope climbing device that provides a climber with the use of his or her full range of leg motion in connection with two ascenders, is compliant with all applicable safety standards, does not present chronic or long-term health issues such as hip dysplasia, is lightweight, allows a climber free use of both hands during ascent, has a minimal number of components that may impede free movement or catch on tools, branches, etc., and that decreases the effort required to climb while increasing productivity measures without presenting immediate health and safe risks. No known references, taken alone or in combination, are seen as teaching or suggesting the presently claimed apparatus for use in rope climbing.